GSK scores major trial win with potential multiple myeloma blockbuster

GlaxoSmithKline may have scored a major cancer trial win after its belantamab mafodotin hit targets in the pivotal DREAMM-2 trial in relapsed multiple myeloma.

The company announced positive results for the trial in 196 patients with relapsed myeloma, who were refractory to an immunomodulatory drug, a proteasome inhibitor and an anti-CD38 antibody such as Janssen’s Darzalex.

R&D chief Hal Barron said that regulatory filings are due later this year for the drug which has come from nowhere to become a blockbuster contender, as GSK refocuses on oncology after selling off most of its cancer assets to Novartis a few years ago.

The two-arm study met its primary objective and demonstrated a clinically meaningful overall response rate with belantamab mafodotin in the patient population.

Safety and tolerability figures were consistent with that observed in DREAMM-1, the first time in human study of belantamab mafodotin.

GSK already announced findings of DREAMM-1 in March in patients with relapsed/refractory disease, confirming that 60% of patients receiving it achieved an overall response rate after an encouraging interim analysis almost two years ago.

Formerly known as GSK2857916, belantamab mafodotin is an immune-conjugate comprising a humanised anti-B cell maturation monoclonal antibody (BCMA) attached to a cytotoxin via a non-cleavable linker.

The drug linker technology is from Seattle Genetics, and the monoclonal antibody is producing using technology licensed from BioWa.

Belantamab mafodotin had been under the radar until the FDA granted it Breakthrough Therapy designation, and the suggestion is that it could be a more convenient alternative to CAR-T cell therapies targeting BCMA that are in the pipeline.

Celgene has invested in experimental CAR-Ts from bluebird bio and Juno targeting BCMA, and Novartis and Johnson & Johnson are also developing potential cell therapies that could be used in multiple myeloma.

But the experience with CAR-Ts that have made it to market is that they are expensive and cumbersome to administer.

An antibody-based therapy with similar capabilities would likely be popular with prescribers in health systems that are looking for cost-effective medicines.

If approved analysts think the drug could garner sales north of $1 billion a year, which would be most welcome as GSK looks to revive its fortunes.

Sales have been hit as generics have finally been approved for its ageing respiratory blockbuster Advair in the US, after years of delays.

Dr Hal Barron, chief scientific officer and president of R&D at GSK, said: “I am pleased with the results of the DREAMM-2 study and excited about what these data could mean for patients with multiple myeloma who have exhausted other lines of treatment.

“We are on track to file belantamab mafodotin later this year and continue to investigate how it could help even more patients with this disease.”